(746e) Enzyme-Free Method for Amplifying Detection of Cytokines Released by Single Immune Cells Ex Vivo

The human immune system comprises a diverse set of cells that contribute to a productive immunological response.  Characterizing the functional behaviors for individual cells is critical for gaining knowledge on how the various subsets of cells of the immune system operate.  Current bioanalytical technologies are challenged to resolve the diverse functional activities and identities of individual subsets of cells in part because of limited signal associated with events of interest, and the number of parameters concurrently measured in most assays.  In this talk, we will present the integration of microengraving—a soft lithographic method for printing arrays of secreted proteins from thousands of single cells—with a new DNA-based strategy for amplifying signals from immunoassays and protein microarrays.  Combination of this DNA-based method for enzyme-free amplification with microengraving extends the sensitivity of the microengraving for detecting proteins such as human cytokines and chemokines released by individual, activated cells.  This method for amplification lowers the limits of detection for detecting secretions from single cells without requiring enzymes.  The advantages of the method are that it is easy to integrate with standard protocols for processing microarrays, and it is extensible to increase the degree of multiplexed characterization.  Our approach is potentially suited for use in a high-throughput, multiplexed, and directly ex vivo screening of immune cells of interest that may benefit early detection of disease and designing of immunotherapies.